Question: Express your answer as a mixed number simplified to lowest terms. $13\dfrac{2}{4}-6\dfrac{7}{9} = {?}$
Simplify each fraction. $= {13\dfrac{1}{2}} - {6\dfrac{7}{9}}$ Find a common denominator for the fractions: $= {13\dfrac{9}{18}}-{6\dfrac{14}{18}}$ Convert ${13\dfrac{9}{18}}$ to ${12 + \dfrac{18}{18} + \dfrac{9}{18}}$ So the problem becomes: ${12\dfrac{27}{18}}-{6\dfrac{14}{18}}$ Separate the whole numbers from the fractional parts: $= {12} + {\dfrac{27}{18}} - {6} - {\dfrac{14}{18}}$ Bring the whole numbers together and the fractions together: $= {12} - {6} + {\dfrac{27}{18}} - {\dfrac{14}{18}}$ Subtract the whole numbers: $=6 + {\dfrac{27}{18}} - {\dfrac{14}{18}}$ Subtract the fractions: $= 6+\dfrac{13}{18}$ Combine the whole and fractional parts into a mixed number: $= 6\dfrac{13}{18}$